Control device for performance effects of an electronic musical instrument

ABSTRACT

In order to improve a control device for performance effects of an electronic musical instrument there are provided a photoelectric conversion element on the underside of a keybed below the manual keyboard of the electronic musical instrument and also a light source near the front side of the bottom part of the instrument so as to face the photoelectric conversion element. By interrupting a light beam from the source to the photoelectric conversion element with part of the player&#39;&#39;s body, the resistance of the element is caused to be varied to actuate a relay, thereby permitting the use of circuits of performance effects such as sustain, vibrato and reverberation.

United States Patent Tomisawa 1451 May 16, 1972 [72] Inventor:

[73] Assignee:

Norio Tomisawa, Hamamatsu, Japan Nippon Gakki Seizo Kabushiki Kaisha, Hamamatsu-shi, Japan 22 Filed: Dec. 23, 1970 211 Appl.No.: 100,896

[30] Foreign Application Priority Data Dec. 25, 1969 Japan ..44/122708 [56] References Cited UNITED STATES PATENTS l/l964 Peterson ..84/l.25 5/1970 Anderson et al ..84/DIG. 19

3,514,522 5/1970 Mussulman ..84/DlG. 19 3,525,796 8/1970 Franssen ..84/1.24 X 2,432,527 12/1947 Lang .84/1 O1 X 3,461,217 8/1969 Omura et al. 84/].26 X 3,045,522 7/1962 Markowitz et a1.. ....84/1 27 3,316,341 4/1967 Peterson ....84/1.24 3,499,094 3/1970 Hoshino ..84/1.24

Primary Examiner-Lewis H. Myers Assistant ExaminerU. Weldon Attorney-Flynn & Frishauf ABSTRACT In order to improve a control device for performance effects of an electronic musical instrument there are provided a photoelectric conversion element on the underside of a keybed below the manual keyboard of the electronic musical instrument and also a light source near the front side of the bottom part of the instrument so as to face the photoelectric conversion element. By interrupting a light beam from the source to the photoelectric conversion element with part of the players body, the resistance of the element is caused to be varied to actuate a relay, thereby permitting the use of circuits of performance effects such as sustain, vibrato and reverberation.

7 Claims, 2 Drawing Figures BACKGROUND OF THE INVENTION The present invention relates to an electronic musical instrument provided with circuits of performance effects such as sustain, vibrato and reverberation and more particularly to an improved control device capable of obtaining such performance effects using part of the players body.

The conventional electronic musical instrument, such as an electronic organ, has a knee lever swingably disposed on the underside of a keybed below the manual keyboard. The knee lever is disposed in association with circuits of performance effects such as sustain, vibrato and reverberation so as to obtain the respective effects by being operated by .the players knee. However, such knee lever has the drawbacks that its operation requires a certain amount of physical force on the players part and that if the force applied is unduly great, the knee lever will be bent with the resulting damage of a switch or switches interlocking therewith. There is a further possibility of the knee lever being broken during movement or transportation.

It is accordingly the object of the present invention to provide a control device for performance effects of an electronic musical instrument whose operation does not rely on any mechanical means but can be easily effected by the players knee or foot without applying any physical force at all.

SUMMARY OF THE INVENTION According to the present invention, there is provided a control device for performance effects in an electronic musical instrument which comprises a photoelectric conversion element disposed on the underside of a keybed below the manual keyboard of said instrument and coupled to a control circuit to control performance effects. A light source is positioned near the front side of the bottom part of said instrument so as to face the photoelectric conversion element and project light thereon, whereby, when a light beam from the source to the photoelectric conversion element is interrupted by part of the players body, the resistance of the photoelectric conversion element varies, thereby selectively actuating performance effect circuits.

BRIEF EXPLANATION OF THE DRAWING FIG. 1 is a perspective view of an electronic musical instrument according to the present invention; and

FIG. 2 is a block diagram of an electronic musical instrument having a control device according to the present invention.

DESCRIPTION OF THE PREFERREDEMBODIMENTS Referring to FIG. 1, there is fixed by proper means a photoelectric conversion element 4, for example of CdS type to the underside of a keybed 3 below the manually operable keyboard 2 of an electronic musical instrument 1 such as an electronic organ. The photoelectric conversion element 4 is desired to have such directivity as only permit reception of the light beam from a later described light source. In order for the photoelectric conversion element not to be affected by the indoor illumination, it is preferred that the element be enclosed in a suitable casing perforated with an aperture or within the musical instrument itself at such a point as to face the aperture formed in the keybed, directing only to the light source. Where the electronic musical instrument is provided with a pedal keyboard 5, the photoelectric conversion element 4 is positioned in the right of the pedal keyboard 5.

On the other hand, there is provided a light source 7 on the front side of the bottom part of the front panel 6 of the musical instrument 1, that is, near the players right foot, so as to face the photoelectric conversion element 4. The light source or lamp 7 is lit upon the closure of the power switch of the musical instrument 1. It is preferred that a light beam 8 from the ranged adjacent to the manual keyboard.

FIG. 2 represents a schematic block diagram of an elecsion control 13 and a main amplifier 14 to drive a loudspeaker 15.

The sustain keyer 11 comprises, as illustrated, a transistor a parallel connection of a capacitor 113 with a series connection consisting of a resistor 111 and a key switch 112 which are connected between the emitter of transistor 110 and one power source terminal; a series connection of resistors 114 (small resistance, i.e. 2 kiloohms) and 115 (large resistance, i.e. 200 kiloohms) connected between the emitter of transistor 110 and a cut-off bias source; a sustain selector switch 116 (normally closed type) and a normally closed contact 117 of a later described relay 123, the switch 116 and the closed state as shown during a nonselected period.

There will now be described the operation of the sustain keyer 11. The capacitor 113 connected to the emitter of the transistor 110 is normally charged by the cut-off bias source to render the transistor 110 nonconductive. Accordingly, tone signal supplied from the tone Accordingly, the tone signal from the tone generator 10 can be derived from the collector of transistor 110. When the key 1 16 is kept closed) to render the transistor 1 l0 nonconductive again. When the sustain selector switch 116 is mainpulated and opened, the capacitor 113 is charged slowly, that is, with a large time constant through the resistors 114 progressively bringing the transistor 110 to a nonconductive a sustain effect.

There is further provided a vibrato oscillator 16 as one of the performance effect circuits. Output from the oscillator 16 is conducted to the tone generator 10 through a series connection consisting of a vibrato selector switch 118 and the normally open contact 119 of the relay 123. In the tone generator stop tablet switches 9. However, unlike the sustain selector switch 116, the vibrato selector switch is opened during a nonselected period, and becomes closed when mainpulated.

The main amplifier 14 is connected in parallel with a series cludes a transistor 122 the collector of which is connected to one source terminal through a relay coil 123, the emitter of which is connected to the other source terminal through a resistor 124, and the base of which is connected to a juncture between a resistor 125 and the photoelectric conversion element 4 which are connected in series across the power source.

While the light beam 8 is projected on the photoelectric conversion element 4 from the light source connected to a power source 22, the element has a small resistance, rendering the transistor 122 nonconductive and in consequence the relay 123 nonenergized. However, when the light beam 8 from the light source 7 to the photoelectric conversion element 4 is interrupted by part, or the right knee or right foot of the player, then the element increases in resistance to raise the bias voltage impressed on the base of transistor 122, and in consequence renders the transistor 122 conductive. As a result, the relay 123 is energized to actuate the relay contacts 117, 119 and 121 at the same time. In this case, the relay contact 117 included in the sustain keyer 11 is opened, while the other relay contacts 119 and 121 are closed.

Where there is selectively used at least one of the sustain selector switch 116, vibrato selector switch 118, and reverberation selector switch 120, then it will be apparent that the resulting performance effect circuit is effectively used to produce a desired performance effect.

Further, if the photoelectric conversion element 4 and light source 7 are so set as to permit adjustment over a range of for example, several centimeters crosswise or lengthwise, then it will desirably offer convenience in determining a most appropriate position for these units 4 and 7 according'to the physical characteristics of the player and his posture with respect to the electronic musical instrument.

What is claimed is:

1. In an electronic musical instrument having a keyboard, a keybed below said keyboard, and performance effect circuitry; a control device for controlling said performance effect circuits comprising:

a photoelectric conversion element disposed on the underside of said keybed;

a light source located in the front of the bottom part of said musical instrument projecting a light beam to said photoelectric conversion element, said light beam being positioned to be interrupted solely by a member of the body of a player to vary the intensity of the light reaching said photoelectric conversion element, said photoelectric conversion element exhibiting an internal resistance which varies in response to the intensity of the light projected thereon; and

a control circuit connected to said photoelectric conversion element and coupled with said performance effect circuitry for selectively rendering said performance effect circuitry operative and inoperative according to the internal resistance of said photoelectric conversion element.

2. A control device according to claim 1 wherein said control circuit includes a transistor having a collector, an emitter and a base; first and second power source terminals; a relay having a coil and contacts, said coil being connected between said collector and said first power source terminal, and said contacts being coupled to said performance effect circuitry; a first resistor connected between said emitter and said second power source terminal; and a second resistor connected between said base and said first power source terminal; said photoelectric conversion element being connected between said base and said second power source terminal.

3. A control device according to claim 2 wherein said performance effect circuitry comprises a sustain keyer including a selector switch which is closed during a non-selected time, said relay having a normally closed contact which is connected in parallel to said selector switch.

4. A control device according to claim 2 wherein said performance effect circuitry comprises a vibrato oscillator including a selector switch which is opened during a nonselected time, said relay having a normally open contact connected in series with said selector switch, the output from said vibrato oscillator being coupled out serially through said selector switch and said normally open contact.

5. A control device according to claim 2 wherein said performance effect circuitry comprises a reverberation circuit including a selector switch which is opened during a nonselected time, said relay having a normally open contact connected in series with said selector switch, the output from said reverberation circuit being coupled out serially through said selector switch and said normally open contact.

6. A control device according to claim 1, wherein said performance effect circuitry comprises a plurality of performance effect circuits and selecting means coupled to said circuits for selective performance of a performance effect when said circuitry is rendered operative by said control circuit.

7. A control device according to claim 2, wherein said performance effect circuitry comprises a plurality of performance effect circuits, one of said performance effect circuits being a sustain keyer including a selector switch which is closed during a non-selected time, said relay having a normally closed contact which is connected in parallel to said selector switch; another of said performance effect circuits being a vibrato oscillator including a selector switch which is opened during a non-selected time, said relay having a normally open contact connected in series with said vibrato oscillator selector switch, the output from said vibrato oscillator being coupled out serially through said vibrato oscillator selector switch and said normally open contact; and another of said performance effect circuits being a reverberation circuit including a selector switch which is opened during a non-selected time, said relay having a normally open contact connected in series with said reverberation circuit selector switch, the output from said reverberation circuit being coupled out serially through said reverberation circuit selector switch and said normally open contact. 

1. In an electronic musical instrument having a keyboard, a keybed below said keyboard, and performance effect circuitry; a control device for controlling said performance effect circuits comprising: a photoelectric conversion element disposed on the underside of said keybed; a light source located in the front of the bottom part of said musical instrument projecting a light beam to said photoelectric conversion element, said light beam being positioned to be interrupted solely by a member of the body of a player to vary the intensity of thE light reaching said photoelectric conversion element, said photoelectric conversion element exhibiting an internal resistance which varies in response to the intensity of the light projected thereon; and a control circuit connected to said photoelectric conversion element and coupled with said performance effect circuitry for selectively rendering said performance effect circuitry operative and inoperative according to the internal resistance of said photoelectric conversion element.
 2. A control device according to claim 1 wherein said control circuit includes a transistor having a collector, an emitter and a base; first and second power source terminals; a relay having a coil and contacts, said coil being connected between said collector and said first power source terminal, and said contacts being coupled to said performance effect circuitry; a first resistor connected between said emitter and said second power source terminal; and a second resistor connected between said base and said first power source terminal; said photoelectric conversion element being connected between said base and said second power source terminal.
 3. A control device according to claim 2 wherein said performance effect circuitry comprises a sustain keyer including a selector switch which is closed during a non-selected time, said relay having a normally closed contact which is connected in parallel to said selector switch.
 4. A control device according to claim 2 wherein said performance effect circuitry comprises a vibrato oscillator including a selector switch which is opened during a non-selected time, said relay having a normally open contact connected in series with said selector switch, the output from said vibrato oscillator being coupled out serially through said selector switch and said normally open contact.
 5. A control device according to claim 2 wherein said performance effect circuitry comprises a reverberation circuit including a selector switch which is opened during a non-selected time, said relay having a normally open contact connected in series with said selector switch, the output from said reverberation circuit being coupled out serially through said selector switch and said normally open contact.
 6. A control device according to claim 1, wherein said performance effect circuitry comprises a plurality of performance effect circuits and selecting means coupled to said circuits for selective performance of a performance effect when said circuitry is rendered operative by said control circuit.
 7. A control device according to claim 2, wherein said performance effect circuitry comprises a plurality of performance effect circuits, one of said performance effect circuits being a sustain keyer including a selector switch which is closed during a non-selected time, said relay having a normally closed contact which is connected in parallel to said selector switch; another of said performance effect circuits being a vibrato oscillator including a selector switch which is opened during a non-selected time, said relay having a normally open contact connected in series with said vibrato oscillator selector switch, the output from said vibrato oscillator being coupled out serially through said vibrato oscillator selector switch and said normally open contact; and another of said performance effect circuits being a reverberation circuit including a selector switch which is opened during a non-selected time, said relay having a normally open contact connected in series with said reverberation circuit selector switch, the output from said reverberation circuit being coupled out serially through said reverberation circuit selector switch and said normally open contact. 